[rsaavedra]

Ok I already built a Dynahi. It's not completely finished, but in any case, it's dormant in a storage place. so I don't have a headphone amp with me right now. Very likely I might ship my stuff before end of year, but still the DIY bug is biting my ear again, so I'd like to get my hands dirty on another DIY project. Now here some facts and restrictions:

Fact 1: Don't have my DIY tool set with me. Just bought a soldering iron and a multimeter however. Will buy some other few minimal tools to be able to do the project while all my stuff is still away.

Fact 2: Here in Venezuela the first and so far only electronics store I have visited has absolutely no 1% resistors. Will keep looking, but there might be a provisioning problem there.

Fact 3: edited-out since Mouser ships internationally.

And now some questions.

Question 1: What is the current highest-end DIY portable amp? (Is it the Pimeta?)

Question 2: How much more work or time does building a complete M3 take (power supply included) compared to let's say, building a Pimeta, or the DIY amp that answers question #1?

Question 3: To build an M3 is supposedly much easier than to build a Dynahi. Does building an M3 require doing any not so well documented calibrations or special adjustment after boards are populated? (thinking of the DC offset adjustment for the Dynahi, which required purchasing extra trimpots and waiting another week to get them delivered). Also do I need two multimeters for anything? (thinking of matching transistors for the Dynahi) Or any special tool for any particular requirement?

Question 4: Would you recommend just going easy for now and building a good portable that will use batteries because of the tools and components limitations, skipping the power supply also, or would you suggest just go all the way and build a full M3. Or something else? Possibly, selling the Condor power supplies I'm using for the Dynahi, and building a power supply for it?

Suggestions welcome, thanks much!
Cheers,
Raúl

 

[n_maher]

Quote:

Originally Posted by rsaavedra Question 1: What is the current highest-end DIY portable amp? (Is it the Pimeta?)

Technically the PPA. It's transportable at least and some would argue portable. Pocket-sized, no - but you can build it in a Hammond w/ the battery board and it'd be a killer lap-top setup. The PIMETA is considerably easier and will take less time, money, skill and patience. Not to mention that it'll last longer and run on fewer batteries and fit in a smaller enclosure

.

Quote:

Question 2: How much more work or time does building a complete M3 take (power supply included) compared to let's say, building a Pimeta, or the DIY amp that answers question #1?

About the same, in either case. I built my PPA, power supply not included, in 4 hours. I've been known to bang out a STEPS in around an hour. Count on another 5 hours for case work (by my count) for any amp. It always takes me a long time to case up an amp, unless it's a MINT.


Quote:

Question 3: To build an M3 is supposedly much easier than to build than a Dynahi. Does building an M3 require doing any not so well documented calibrations or special adjustment after boards are populated?

No. Quote:

Or any special tool?

Nope, just your average DMM and a small screwdriver for the trimpots.

Quote:

Question 4: Would you recommend just going easy for now and building a good portable that will use batteries because of the tools and components limitations, skipping the power supply also, or would you suggest just go all the way and build a full M3.

The case work for a portable (PIMETA or other) would be a lot easier given limited access to tools. And eventually you'll have the Dynahi finished right, so a portable might round out the collection nicely.

That's my 2¢,

Nate

 

[rsaavedra]

Quote:

Originally Posted by n_maher The case work for a portable (PIMETA or other) would be a lot easier given limited access to tools. And eventually you'll have the Dynahi finished right, so a portable might round out the collection nicely.

Thanks Nate! What you mention sounds pretty good, Dynahi would be my home amp, and I could have a portable amp which so far I'm missing.

The Pimeta is sounding attractive because of that, plus simplicity and speed, and given the restrictions. Hmm...

Keep suggestions coming guys!

 

[rsaavedra]

Bumpity bump

 

[Jazper]

Nate is right, but an M3 is an M3, and according to a recent thread, not that inferior (if at all) to a dynahi.

The M3 cannot be a portable amp. It requires too much current and produces too much heat. A basic M3 consumes 330mA or so. It is easy to build, but you do need a multimeter and a small flathead screwdriver. I'd guess for an average builder it is about 3-6 hours work from go to woah (without casework, possibly with power supply). Most of the work is in organising the parts - once you have those, everything else is peachy.

Only advice I have for you is to get extra q5 transistors in case you accidently fry them by slipping and to populate the led even if you haven't set up the biasing yet.

You will also need M3 or M4 self tapping metal screws to secure the heatsinks.

Calibration instructions are on AMB's page - the procedure takes about 10-15 minutes or so. With a checkup about 45 minutes later.

Mouser ships internationally - I don't see why you'd have to do multiple shipping to miami and then to where you are.

 

[rsaavedra]

Quote:

Originally Posted by Jazper Mouser ships internationally

Ah, didn't know this, very good to know, thanks Jazper!

 

[rsaavedra]

Nighty bump

 

[nikongod]

set 300b tube monoblocks.

 

[Pars]

Maybe you oughta build the "Mystery Amp" from the Hamilton meet thread? Really simple, you could probably source all the parts right in Venezuela (IRF510, a couple of decent caps, 12V supply). Info about it is here. It seemed to go over quite well at the Hamilton meet. I may build one myself... hehe.

 

[rsaavedra]

Nighty bump

 

[aerius]

Build the Objective Interim 6SN7 Push-Pull Headphone Amp

You'll need to scrounge a power transformer that puts out around 170-180 volts AC, a power supply of some sort for the tube heaters, and a couple output transformers. Works great with high impedance 'phones such as the Senn 580/6x0 and of course my AKG K340, but has way too much gain for my Grado 225. If you choose to build one, you'll be only the 2nd person in the world (AFAIK) to have one.

 

[looser101]

Quote:

Originally Posted by Pars Maybe you oughta build the "Mystery Amp" from the Hamilton meet thread? Really simple, you could probably source all the parts right in Venezuela (IRF510, a couple of decent caps, 12V supply). Info about it is here. It seemed to go over quite well at the Hamilton meet. I may build one myself... hehe.

A very simple amp and very good sounding. I used 2x470uF 25V Elna Cerafines per channel and they sound rather nice.

Two words of caution:
1. It draws alot of current. Over 800mA idling. I built a TREAD with an LM317 and it was curent limited (distorted at high volume). It's much happier with an LM350.

2. It gets very hot. Big heatsinks are recommended.

I was very happy everyone enjoyed listening to it at the Hamilton Head-Fi Meet.

All the best with your builds,

-R-

 

[Sigurd Ruschkows]

Borbely Audio has some great DIY kits. For ex the class A SE headphone amp
at http://www.borbelyaudio.com/eb602210.asp

I built one last month. Very simple to assemble. Now I have finished the unregulated and regulated PS and am working on the case.

Borbely's best headphone amp is probably the ALL FET Line amp that can drive headphones, too.
http://www.borbelyaudio.com/eb1198116.asp

Or why not the simple Superbuffer (with some gain) and some extra pairs of JFETs for an all JFET headphone amp
http://www.borbelyaudio.com/eb602403.asp

I have some Superbuffers as line amps and they sound superb!


Sigurd

 

[rsaavedra]

Wow thanks a lot for all the suggestions!!! Quite impressive recommendations.

I will have trouble comparing all of these though. I can differentiate with some degree of accuracy components drawn on a circuit diagram, but pretty much that's as far as I go about analyzing electronics circuits

Have no knowledge on how to assess circuit topology advantages, disadvantages, strengths etc. I feel just like a kid would in front of a circuit diagram: basically blind.

Once Dr. Jan Meier warned me that trying to build a tube amp as a newbie (even as an expert DIYer) is quite a risk because high voltages are involved. Not sure if I should attempt one.

One reason I would face the risk and try building a tube amp would be if there was a sort of "open-source" circuit diagram for the MicroZOTL. Afaik there isn't though. Imho the Microzotl is one of the best amps I've ever heard. Tried it with HD600's, HP2's, and R10's, liked it better than Wayne's hefty SDS Supra with the same headphones.

 

[rsaavedra]

bumpy